Screed for cement surfaces



NOV'. 2, 1954 R, G, BARNES y 2,693,136

SCREED FOR CEMENT SURFACES Filed May 7, 1949 IIl l 37 4511:: I9 45",

United States Patent Oiiice SCREED FOR CEMENT SURFACES@ Ralph-G.-IBames, Brtland'0reg. assignerr ofrone-half -to Jessev J.Gard, Portland;lOleg and. one-halt to Master" Vibrator Company@ Dayton Ohiog, a.-corporartion,of.0hio'- Application.May'1,.1949,.seriarNa9zgo11'sacianns: (c1. lski-4er This; invention: relatesto'..concrete-vibratorsioffthe kindcharacterized;Sby/-aevibratony'screed on'beami.

Initheuse'of devicesiofirtlristypeg-'thecbeamiszsupported at oradjacentto its ends and is dragged over the surface the aworlc', torexample;l a: roadway in: which: fresh. con- 'cretehasfbeenrpoured Tfheatendency] ofr'thebearni tosa'g or'bow'when. sot supported and v'usedhaspreclude'di the use"V 'of' elongated beams', which' would be.more-efficient and* 4desirable in: some.l applications.'lyiorelzwer',.inA equipnient ofi this' type'. no means' have beenheretofore 'provided whereby a' predeterminedlbow or-'arch may be.; ad-

.justajbly imparted' to'- the' beam', adapting` th'eifscre'ed. for

work uponiconcave andoonvex surfaces. v

The instan-t invention: contemplates an'y improvement uponv concretescreeds. ofr the class described to' the' end tliati bothl limitationsabove. mentionedi maye bel obviate'd. A"trussing.l of the scree'dfor'bearni is'proposed throughl 'a 'rigid"br-idge 'resisting sagging ofl'therscreedpai feature' of the'- truss residing inadjustmenti means:whereby the-.truss 'may bev lengthened andfshort'ened relativelyfto thescreed.

tionas wellf'asfthe nreansandimodeof operation ofv-ibratory'scre'ed'b'eams 'whereby such. deyiceslm'ay'not only beeconomically manufactured-but w-ill 'b'e'tnoreweii'cientand satisfactoryin' use, adaptable toi-'a1 Widefvariety of work, having relatively' fewpartsrandf be' )unlikely 'to igetjoutfof repair.

Ai further' object 'of the' invention'. istoprovidel in'fga yibratoryscreed rn'eans'- for -adjustab'ly/iiexing.' the* screed 'for'the'finishing of 4"con'teuredisurfaces.

Al further4 objeet of' the inventioni isntoiproyid'e' a screed beam of1'extraordinary length; which may beraceurately controlled aste-contour.'

- AA further' lobject 'off the' linventiorn istov provider in' anelongated' vibratery' screed means forfcontrollingftheiiiexingthereofintermediate' 'itswidely spacedlpoints lof supportsfurther'object' vof thernvention isfto'Y simplifyI 'the 'meansvandi modefof-."adju'stab'hy securing supportinganemitiers tothetends-ofarvibratonyfscreed.

A further object of'th'eiinvention lis toprovidefavibra- 'toryscreedpossessing. thezadvant'ageous' structural features, tliei-nlierent meritorious 4chara'oteristics and themodeofloperatiorthereinmentionedi.

With the above'prirnary'an'd.s.otller` iincidentalobjectsin Viewy 'as'will; more'r :fully appean ini thespecicationgnthe :invention intended?tov be 'protected #byl Letters :Patent 'consists' of vfthe featuresofoonstructionnfthe pants and -rcombinationsthereof; .andthe .mede .ofoperatiomrasshereinafter described.l or illustrated ini the accompanyingdrawings; or theirequivalent.

Referring to the accompanying drawing, wherein is` found the preferredbut obviously not necessarily the only form of'embodinent off'theinvent-ion;

Fig. 1 is a. perspective view of a vibratory screed in accordancewith't'lie instant'- invention, showing a manner of use thereof;

Fig; '.2 is aA view of the vibratory screed 1n .-frontfelevaftionpartlydiagrammatic, indicating yliow the` beamamay assume'aiiexed contour; y

Fig.' '3 issa' detail View in frontelevatron oftjon eendA of thesoreedgshowing the mounting meansffor theqbeam;A

vflat base. portion 1'4 .(jsee .Ei

sof. the. web portion in conjunction with the beannis productive of '.ageneral respective ends. thereof. and .iis

2,693,136 `Patented Nov. 2,. 1954 Fig. 4 an .end view of the' screedpartly in section', beingftaken. alongthe line4-4ofFigz 3';

Fig. 5 is a' fragmentary view similartoFig.' 4'but. look.- ingat"tlie.-opposite endg' being taken"along^ the line 5 5 ofFig. 3;

Fig. 'fisa detail Viewl partly'broken' away of" the-acfjustment meansembodied! in lthe tr-nss;, and

Fig. 7 is a' detail view ,partly in section showingg'tlie linkage.interconnecting the truss y,and thescreed.

Like. `parts.-are' indicated by similar cliaracters'ofi'referencethroughout the several views:

Thepresent disclosure' represents a further' developmentandlimprovement' inthe screed shown and claimed inmy Patent No'.2,5.42;979,.issued'February'27;A 1951'.

Referring to fthe drawings .a' vibratoryV screed lin .accord-.ancewitlithe .instant invention is shown being used .the construction.offa roadway or. .the like, spaced ledgesfor side forms 1102providingsupportfor the deviceat .itsoppositeend's.. The screedisguideditsadvanceoverthe fresh' concrete byr-menwalkingfon'the. ledges 10andproduces. a smoothcompactedsurface 11 asv-compared with theroughuninislied .surface 12Lwhieh. may' be seenin advance .of .the device..

The. screed' comprises anl elongated beam ,13 of inv erted. T-shape,.the beam being. formed with a broad g.. 4) and-an upstanding webport-ion. 15.. Secured. as. by welding, to the upper edge IS-ofthe beamis-a tube 16 which,

and4 uniform amplitude of. vibra-tion. Centrally of the beam: 13. U-bolts,.17 project :outwardly and i upwardly from the; oppositesides of'web. vportion 1'5' and support. a .table .18 upon whichfis mounted a ysource. of. powen 19' (a .gasoline enginefor electric motor). The powersource .19tv is connected; to a. rotary, unbalanced weight (not shown),arranged'. beneathy .the table,. rotation. of. which serves to. vibratethe .beam 13. to compact' the surface on. which. it. rests.

The. structure so. far. describedf is substantially. the same .as thatshowmand. describedin my above-identifiedlcopending application for.United' .Statesv Letters .Batent For. better vihratory;` action the.ybeam 15 is resiliently mounted .uponfits supports. Asshown .in Figs. 3and4, therer isfprovided adjacent eachv end of the .beam a twopart clampL21. arra-ngedto be compressed'into gripping engagement.' with,thertub'e .I6 by. adjustment of. nut assernblies .22.. Gverlying. .theupper. end. ofl each. clamp .Zl iswone endof a leaf .spring ..23.securedr between. the clamp. .and;.a -plate 2`.4. by a. nut'. and' bolt.assembly 2'5. Each..spring..23' .extendsY axially .of the beam, I3`toward fastened; at. its opposite endtnfa bracket '26' .of inverted.U.-shape. The vopposing 'legs .of-each)` .bracket '26 extend downwardinembracing relationto ,the .tube i161* and beam 13 and are bent 0ut ward.at their. ends to...de'ne. flanges 27' lyingin aplane paralleLto vthebase 114i of-l the .bearn.1`3`. Securedto the angesl are. Througlitheuse.of`sliirns..2'9 placed -between. the. feet. S285 and fflangeslTaccurate ,positioningo ttieeeLrnay beaccornplished'. order. that theymay'l'ie in a plane slightly lower than the base ofthe bearn13 whichthus isheld in an elevated position yieldin'gly' supported. by 'the'leaf springs' 2'3l The 'feet 28' are' adapted "to rid'e` upon a. track'or'slid'eway, 'for example, the ledges i shown' in Fig. l'.

According t'o the `width 'of the' :surta'ce-being' worked, the distance'between' suchtracksA or'slideways'will vary. Adiust'rnent' of' the.mounting' mea n'srel'ative' to 'the' 'beam to allow for sucl'variationis easily accomplishedlrnerely .by loosening, ,the attachment means 22,coi-npriserl` in clampsl, whereupon theseparate assemblies comprisingclamps 21',..springs 23, brackets. 261 and'feet .'2`8 may be .sld'.along -tliemtlibe. 15 to. annew position. of adjustment.

vXhenso positioned;l the nutassemblies .'22 are. again ,.stantinvention, there are mounted upjonc'the opposite ends thereof a pair ofupstanding elements 32, one element of each pair being secured onopposite sides of the web portion at each end of the beam. Theupstanding arms of each pair of elements 32 project above the associatedspring mounting means and may be formed with registering openings 33 toreceive a lifting bar or handle 34 (see. Fig. 1). Supported between sucharms, beneath the openings 33, is a pivot pin 35, the pins defininganchors for the opposite ends of the truss.

The truss itself is indicated generally at 36 and is made up of a pairof rigid tubular members 37 and 38, each having a yoke 39 at its outerend pivotally mounted upon a respective pin 35. The members 37 and 38extend toward one another from their anchor points in overlying spacedrelation to the beam 13 and engage one j another in a telescopingconnection. As shown in Fig. 6, the left hand truss member 37 has ascrew threaded stud 41 projecting therefrom upon which is mounted ashouldered stop nut 42 and a lock nut 43. The outer end of the stud 41is received in the inner end of truss member 38 which limits against thenut 42, a predetermined fixed relationship of the parts being maintainedagainst the effects of vibration by turning the lock nut 43 up intofrictional engagement with the nut 42.

Centrally of the beam 13, suspension means are provided interconnectingthe beam and the truss 36. These means comprise two pairs of posts 44fixed to the beam 13 on opposite sides of the engine 19. In overlyingrelation to each pair of posts 44 is a saddle 45 secured to the truss36. The opposite ends of each saddle 45 are connected to its associatedposts 44 by links made up of a chain 46 and a coil spring 47, the linksbeing crossed diagonally relatively to each other.

The suspension devices and the truss 36 jointly cooperate in inhibitingundesired sagging or bowing of the beam 13 and in obtaining apredertermined exure of the beam between arched and bowed extremes. Inthis connection, when an elongated beam such as the beam 13 is supportedat or adjacent to its ends it tends to flex downward or to assume abowed shape. Such tendency may be resisted or controlled by an initialadjustment of the stop nut 42 in the truss which will limit the inwardtelescoping motion of the truss members 37 and 38 to a predeterminedextent. Further, by adjustment of the nut 42 outwardly along the stud 41the effectivevlength of the truss 36 may be extended to enforce anarching of the beam 13. Such an adjustment is illustrated in Fig. 2wherein the beam is shown in full lines in a normal flat horizontalplane and is shown in dotted lines as set to an arched form byadjustment of the truss.

Thus, by expansion or contraction of the truss member 36 the exure ofthe beam 13 is readily controlled and regulated although the beam is ofextraordinary length and only supported adjacent its extremities. Ofparticular importance is the fact that the present means ofstrengthening the elongated beam in no way affects its vibratory motionor decreases its eiciency. Although the truss member is restrained byits connection to the central portion of the beam, which is necessary inorder to increase the stability of the assembly and prevent tipping orside-sway of the truss member, such tie or connection is of a resilientcharacter so as not to interfere with or decrease the desired vibratorymotion of the screed.

From the above description it will be apparent that there is thusprovided a device of the character described possessing the particularfeature of advantage before enumerated as desirable, but which obviouslyis susceptible of modification in its form, proportions, detailconstruction and arrangement of parts without departing from theprinciple involved or sacrificing any of its advantages. l

While in order to comply with the statute the invention has beendescribed in language more or less specific` as to structural features,it is to be understood that the invention is not limited to the specificfeatures shown, but that the means and construction herein disclosedcomprise bt one of several modes of putting the invention into e ect.

Having thus described my invention, I claim:

1. A concrete vibrator, including an elongated beam, vibratory means onsaid beam, means supporting said beam at its ends for motion over aconcrete surface, said beam tending by reason of such support to flexdownward, a truss interconnecting the ends of said beam and extending inoverlying spaced relation thereto, and resilient yielding meansinterconnecting said truss and said beam centrally thereof.

2. A concrete vibrator according to claim 1, characterized by meansshortening and extending the length of said truss to effect acorresponding change in the exure of said beam.

3. A concrete vibrator including an elongated beam, vibratory means onsaid beam, means supporting said beam at its ends for motion over aconcrete surface, said beam tending by reason of such support to flexdownward, a truss for said beam comprising rigid truss members anchoredat their one ends to respective ends of said beam and extending towardone another in overlying spaced relation to the beam and joined in anadjustable connection at their opposite or adjacent ends, saidconnection including means to vary the effective length of said truss,and resilient 'suspension means in- 'ltjerconnecting said truss and saidbeam centrally of the earn.

4. A concrete vibrator including an elongated beam, vibratory means onsaid beam, means supporting said beam adjacent its ends for motion overa concrete surface, said beam tending by reason of such support to exdownward, a truss rigidly interconnecting the ends of said beam andlying in spaced overlying relation to the length thereof, and resilientsuspension means interconnecting said truss and said beam centrally ofthe beam.

5. A concrete vibrator including an elongated beam, vibratory means onsaid beam, means supporting said beam adjacent its ends for motion overa concrete surface, said beam tending to flex downward between saidsupports, a truss for said beam comprising rigid arcuate truss membersanchored at their one ends to respective ends of said beam and extendingtoward one another in overlying spaced relation to the beam into atelescoping connection at their opposite or adjacent ends, a nut on oneof said truss members engageable by the other of said members to limitinward telescoping motion of said members and thereby limit the downwardflexure of said beam, and a screw threaded mounting for said nutpermitting adjustment thereof to vary the eifective length of said trussand thereby to vary the exure of said beam between bowed and archedextremes.

6. A concrete vibrator according to claim 5, characterized by resilientsuspension means interconnecting said truss and said beam centrally ofthe beam.

7. An elongated screed beam for finishing cementuous surfacesresiliently suspended upon a pair of adjustably fspaced feetcharacterized by a truss member interconnected with the opposite ends ofthe beam and extending in overlying parallel spaced relation with saidbeam, means for varying the length of said tmss to control the flexureof said underlying beam, resilient links interposed between the beam andoverlying truss centrally thereof and means for adjustably securing thespaced feet to the beam independently of the connection of the trussthereto comprising an expansible and contractible clamp carried by eachof said feet and means for contracting said clamp upon the beam in anydesired position of adjustment relative thereto, the construction andarrangement being such that the feet may be adjusted relative to thebeam irrespective of the interconnection of the truss member with theends of the said beam.

8. In a semi-flexible elongated vibratory screed beam, rigid tie meansinterconnected with opposite ends of the beam and extending intooverlying parallel spaced relation with said beam, means for varying theeffective length of said rigid tie means to thereby control the degreeand direction of exure of said beam, and resilient stabilizing linksinterposed between said beam and overlying tie member and connectedthereto, the links extending in upstanding diagonal intersecting planesto thereby increase the stability of said vibratory screed beam.

References Cited in the tile of this patent UNITED STATES PATENTS NumberName Date 1,388,690 Baker Aug. 23, 1921 1,813,338 Botel et al. July 7,1931 2,038,416 Clifford Apr. 21, 1936 2,306,123 Jackson Dec. 22, 19422,542,979 Barnes Feb. 27, 1951

